I mean, yes the great man theory has already passed well out of fashion in historical analysis, though it is certainly seeing a comeback in some quarters. There is something to these remarkable individuals who manage to channel the turbulent forces of history through their person, forces which you do actually see concentrate in them and then disperse after they die, at varying rates and degrees depending on the social system they are a part of.
But Alexander the Great for example. Yes he had a hell of a story. But then you look at his mother Olympia, who, holey moley, later stopped a whole opposing army after his death and the ensuing civil war by invoking his spirit in ritual, or the accomplishments of his father, Philip II, in uniting the Macedonian empire beforehand. And these are yet other individuals in which these forces are embodied and channeled, who rest atop their own supporting social resources and infrastructure.
Considering the infrastructure and the resources and the energy built up in the incredible rise of the Macedonian empire itself: the dude - Alexander - basically had a launch pad set up for him to take off from.
